Four- and Five-Carbon Dicarboxylic Acids Present in Secondary Organic Aerosol Produced from Anthropogenic and Biogenic Volatile Organic Compounds

To better understand precursors of dicarboxylic acids in ambient secondary organic aerosol (SOA), we studied C4–C9 present SOA formed from the oxidation toluene, naphthalene, α-pinene, and isoprene. were analyzed by offline derivatization gas chromatography–mass spectrometry. We revealed that C4 including succinic acid, maleic fumaric malic DL-tartaric meso-tartaric acid are produced photooxidation toluene. Since barely occurs nature, it is a potential tracer photochemical reaction products. In particles also detected compound its isomer with similar mass spectra to methyltartaric standard; tentatively identified as 2,3-dihydroxypentanedioic isomers. The ratio C4–C5 total toluene had no significant dependence on initial VOC/NOx condition. Trace levels during naphthalene. Malic was α-pinene A trace amount